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iommufd/device: Replace device_list with device_array

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igroup->attach->device_list is used to track attached device of a group
in the RID path. Such tracking is also needed in the PASID path in order
to share path with the RID path.

While there is only one list_head in the iommufd_device. It cannot work
if the device has been attached in both RID path and PASID path. To solve
it, replacing the device_list with an xarray. The attached iommufd_device
is stored in the entry indexed by the idev->obj.id.

Link: https://patch.msgid.link/r/20250321171940.7213-9-yi.l.liu@intel.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Yi Liu 2025-03-21 10:19:30 -07:00 committed by Jason Gunthorpe
parent 75f990aef3
commit 831b40f841
1 changed files with 39 additions and 19 deletions
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58
drivers/iommu/iommufd/device.c
View File

@ -19,7 +19,7 @@ MODULE_PARM_DESC(
struct iommufd_attach {
struct iommufd_hw_pagetable *hwpt;
struct list_head device_list;
struct xarray device_array;
};
static void iommufd_group_release(struct kref *kref)
@ -297,6 +297,20 @@ u32 iommufd_device_to_id(struct iommufd_device *idev)
}
EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, "IOMMUFD");
static unsigned int iommufd_group_device_num(struct iommufd_group *igroup)
{
struct iommufd_device *idev;
unsigned int count = 0;
unsigned long index;
lockdep_assert_held(&igroup->lock);
if (igroup->attach)
xa_for_each(&igroup->attach->device_array, index, idev)
count++;
return count;
}
#ifdef CONFIG_IRQ_MSI_IOMMU
static int iommufd_group_setup_msi(struct iommufd_group *igroup,
struct iommufd_hwpt_paging *hwpt_paging)
@ -371,12 +385,7 @@ iommufd_device_attach_reserved_iova(struct iommufd_device *idev,
/* Check if idev is attached to igroup->hwpt */
static bool iommufd_device_is_attached(struct iommufd_device *idev)
{
struct iommufd_device *cur;
list_for_each_entry(cur, &idev->igroup->attach->device_list, group_item)
if (cur == idev)
return true;
return false;
return xa_load(&idev->igroup->attach->device_array, idev->obj.id);
}
static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
@ -510,20 +519,27 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
rc = -ENOMEM;
goto err_unlock;
}
INIT_LIST_HEAD(&attach->device_list);
xa_init(&attach->device_array);
}
old_hwpt = attach->hwpt;
rc = xa_insert(&attach->device_array, idev->obj.id, XA_ZERO_ENTRY,
GFP_KERNEL);
if (rc) {
WARN_ON(rc == -EBUSY && !old_hwpt);
goto err_free_attach;
}
if (old_hwpt && old_hwpt != hwpt) {
rc = -EINVAL;
goto err_free_attach;
goto err_release_devid;
}
if (attach_resv) {
rc = iommufd_device_attach_reserved_iova(idev, hwpt_paging);
if (rc)
goto err_free_attach;
goto err_release_devid;
}
/*
@ -541,12 +557,15 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
igroup->attach = attach;
}
refcount_inc(&hwpt->obj.users);
list_add_tail(&idev->group_item, &attach->device_list);
WARN_ON(xa_is_err(xa_store(&attach->device_array, idev->obj.id,
idev, GFP_KERNEL)));
mutex_unlock(&igroup->lock);
return 0;
err_unresv:
if (attach_resv)
iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev);
err_release_devid:
xa_release(&attach->device_array, idev->obj.id);
err_free_attach:
if (iommufd_group_first_attach(igroup, pasid))
kfree(attach);
@ -568,8 +587,8 @@ iommufd_hw_pagetable_detach(struct iommufd_device *idev, ioasid_t pasid)
hwpt = attach->hwpt;
hwpt_paging = find_hwpt_paging(hwpt);
list_del(&idev->group_item);
if (list_empty(&attach->device_list)) {
xa_erase(&attach->device_array, idev->obj.id);
if (xa_empty(&attach->device_array)) {
iommufd_hwpt_detach_device(hwpt, idev, pasid);
igroup->attach = NULL;
kfree(attach);
@ -599,10 +618,11 @@ iommufd_group_remove_reserved_iova(struct iommufd_group *igroup,
struct iommufd_hwpt_paging *hwpt_paging)
{
struct iommufd_device *cur;
unsigned long index;
lockdep_assert_held(&igroup->lock);
list_for_each_entry(cur, &igroup->attach->device_list, group_item)
xa_for_each(&igroup->attach->device_array, index, cur)
iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, cur->dev);
}
@ -612,14 +632,14 @@ iommufd_group_do_replace_reserved_iova(struct iommufd_group *igroup,
{
struct iommufd_hwpt_paging *old_hwpt_paging;
struct iommufd_device *cur;
unsigned long index;
int rc;
lockdep_assert_held(&igroup->lock);
old_hwpt_paging = find_hwpt_paging(igroup->attach->hwpt);
if (!old_hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas) {
list_for_each_entry(cur,
&igroup->attach->device_list, group_item) {
xa_for_each(&igroup->attach->device_array, index, cur) {
rc = iopt_table_enforce_dev_resv_regions(
&hwpt_paging->ioas->iopt, cur->dev, NULL);
if (rc)
@ -660,7 +680,7 @@ iommufd_device_do_replace(struct iommufd_device *idev, ioasid_t pasid,
old_hwpt = attach->hwpt;
WARN_ON(!old_hwpt || list_empty(&attach->device_list));
WARN_ON(!old_hwpt || xa_empty(&attach->device_array));
if (!iommufd_device_is_attached(idev)) {
rc = -EINVAL;
@ -689,9 +709,9 @@ iommufd_device_do_replace(struct iommufd_device *idev, ioasid_t pasid,
attach->hwpt = hwpt;
num_devices = list_count_nodes(&attach->device_list);
num_devices = iommufd_group_device_num(igroup);
/*
* Move the refcounts held by the device_list to the new hwpt. Retain a
* Move the refcounts held by the device_array to the new hwpt. Retain a
* refcount for this thread as the caller will free it.
*/
refcount_add(num_devices, &hwpt->obj.users);